nn0c02496_si_001.pdf (1.06 MB)
Proton and Li-Ion Permeation through Graphene with Eight-Atom-Ring Defects
journal contribution
posted on 2020-05-21, 16:34 authored by Eoin Griffin, Lucas Mogg, Guang-Ping Hao, Gopinadhan Kalon, Cihan Bacaksiz, Guillermo Lopez-Polin, T.Y. Zhou, Victor Guarochico, Junhao Cai, Christof Neumann, Andreas Winter, Michael Mohn, Jong Hak Lee, Junhao Lin, Ute Kaiser, Irina V. Grigorieva, Kazu Suenaga, Barbaros Özyilmaz, Hui-Min Cheng, Wencai Ren, Andrey Turchanin, Francois M. Peeters, Andre K. Geim, Marcelo Lozada-HidalgoDefect-free
graphene is impermeable to gases and liquids but highly
permeable to thermal protons. Atomic-scale defects such as vacancies,
grain boundaries, and Stone–Wales defects are predicted to
enhance graphene’s proton permeability and may even allow small
ions through, whereas larger species such as gas molecules should
remain blocked. These expectations have so far remained untested in
experiment. Here, we show that atomically thin carbon films with a
high density of atomic-scale defects continue blocking all molecular
transport, but their proton permeability becomes ∼1000 times
higher than that of defect-free graphene. Lithium ions can also permeate
through such disordered graphene. The enhanced proton and ion permeability
is attributed to a high density of eight-carbon-atom rings. The latter
pose approximately twice lower energy barriers for incoming protons
compared to that of the six-atom rings of graphene and a relatively
low barrier of ∼0.6 eV for Li ions. Our findings suggest that
disordered graphene could be of interest as membranes and protective
barriers in various Li-ion and hydrogen technologies.